The present invention relates to a device for examining anterior sections of the eye with a slit-lamp instrument constructed in accordance with the Scheimpflug principle.
In examinations of the human eye by means of a slit-lamp instrument modified in accordance with the Scheimpflug principle, the section plane in a patient's eye is illuminated via slit illumination and is photographed in a photographic direction which is inclined with respect to the plane of the slit lamp. The photographs are evaluated microdensitometrically and give information as to the condition of the lens and cornea of the human eye.
The basic principle of examining the human eye with a slit-lamp instrument developed in accordance with the Scheimpflug principle is known from the journal Ophthalmologica, Volume 151, 1965, pages 489-491. But the instrument described in that article was developed for scientific research, and its operation is too complicated for practical use. Furthermore, microdensitometric evaluation of photographs is time-consuming and requires trained personnel.
A slit-lamp instrument in accordance with the Scheimpflug principle and intended for practical use on patients has been described in U.S. Pat. No. 4,171,877. That instrument has the disadvantage that, in order to produce different meridian sections in the eye, the slit lamp and camera must be swung by about 180.degree. in front of the patient's eye. Since observation of the slit image is effected in the semicircle above the horizontal, the upper eyelid of the patient must be kept out of the beam, which is unpleasant for the patient.